Method of assembling a relay



Dec. 27, 1960 J. s. BAKER METHOD OF AS SEMBLING A RELAY Filed Feb. 6,1956 lVIETHOD OF ASSEMBLING A RELAY John S. Baker, Skokie, Ill.,assignor, by mesne assignments, to Cook Electric Company, Chicago, Ill.,a corporation of Delaware Filed Feb. 6, 1956, Ser. No. 563,600

8 Claims. (Cl. 29-45558) This invention relates to the method ofassembling a magnetic relay mechanism, whereby parts of the mechanismtotally enclosed within a hollow core of the magnet may be adjusted tohave optimum interengagement, a condition in which the parts operatetogether smoothly and easily, without loose interplay, stiffness, or atendency to bind.

More particularly, the invention is directed to the method of assemblingan electromagnetic relay of a type of construction that is provided withsafeguards against false contact operation caused by forces ofacceleration, shock or vibration. For example, this invention is usefulin assembling a relay having core members positioned to move toward andaway from each other and intercoupled by a motion interlocking mechanismto prevent independent movement of the parts, including the coremembers, and to subject them to counteraction one by another under shockor vibration. Such interlocking mechanism may be composed of pinscoupled one to the other by rocker members. Each pin is secured to adifferent one of the core members and passes loosely through the othercore member, and each of the rocker members is coupled to different andcorresponding end portions of the pins. A contact actuating arm issecured to one of the core members and passes freely through the othercore member, such that movement of the attached core member relative tothe relay frame is required to actuate the relay contacts.

The assembly of this type of relay involves problems that are difficultto solve because adjustment of the parts to eliminate looseness orclearance at the points of engagement, say, between the pins and therocker members, in order to provide positive contact action, has to bemade after the parts are in place and totally enclosed. The eliminationof looseness or clearance at the points of engagement of these partsentails the establishment of intercontact without causing binding or atendency toward stiffness of operation. A still further ditficulty inmaking this assembly involves positioning the parts so that after thelooseness or clearance is eliminated, the various magnetic gaps betweenthe plungers and the back gaps will be in propor proportional relationin order to assure prompt and positive action of the plungers whenenergized. In fact, the essential design and arrangement of these partsincreases the difficulty, because the final assembly and adjustment ofthese parts must be made blind, so to speak, but still so accuratelythat the clearance or looseness between the parts must be eliminatedwith the parts just engaging each other, and no more, in order toachieve proper operation of relay contacts.

An object of the invention is to provide a new and improved method ofpositioning enclosed movable parts to eliminate clearance or loosenessbetween them, said method comprising the performance of an operation ata point exterior to the enclosure to move the parts into engagement witheach other without applying stiffening or binding therebetween.

Another object of the invention is to provide, for an made of anon-magnetic material such as brass.

Z,%5,954 Patented Dec. 27, 1960 electromagnetic relay, a new andimproved method of adjustably assembling its movable parts to assureoptimum performance under any and all severe ambient conditions, saidmethod involving the positioning of the movable parts to eliminateclearance between them preferably from a point exterior of the relay tobring the parts into engagement with each other.

A still further object of the invention is to provide a new and improvedmethod of assembling the parts of an electromagnetic relay and ofadjusting certain of the operating parts whereby to secure properproportioning of the magnetic gaps and to eliminate looseness betweenthese parts in order to effect optimum performance under any and allsevere conditions of use.

Other objects and advantages of the invention will be apparent from the.following description when taken in connection with the accompanyingdrawings which form a part thereof.

In the drawings:

Figure 1 is a longitudinal section of an electromagnetic relay assembledand adjusted in accordance with a method incorporating the features ofthe present invention;

Fig. 2 is a layout of the apparatus for practicing the presentinvention;

Fig. 3 is a longitudinal section similar to the view shown in Fig. 1;

Fig; 4 is an elevation of the inside face of the contact carrying head;and

Fig. 5 is an end view of the sleeve members of the spool to show theanchoring of the end plates therein.

There is shown in Figure 1 an electromagnetic relay having internallydisposed movable elements in the form of plungers or armatures 4 and 5adapted to move toward each other until stopped by the residual orspacer 6 on being energized by coil '7. The armature plungers 4- and 5are made of a magnetic material such as soft iron. The spacer 6 is madeof a nonmagnetic material such as brass in order to prevent the armatureplungers 4 and 5 from sticking together as the result of residualmagnetism. The spool of the relay includes spool ends 8 and 9 carried bysleeve members ltl and 11 respectively between which sleeve memberssleeve 12 extends. Spool ends 8 and 9 and sleeve members 10 and 11 aremade of magnetic material such as soft iron, while sleeve 12 is made ofnon-magnetic material such as brass. Sleeve members Jill and 11 arekeyed at I14 to spool ends 8 and 9 while sleeve 12 is preferably fixedto sleeve members ill and 11 as by tack welding at various points aroundtheir peripheries after the internally disposed elements have beenproperly adjusted in accordance with the features of the presentinvention.

The relay is of a construction that is provided with safeguards againstvarious contact operations caused by forces of acceleration, shock orvibration. The armatures 4 and 5' are intercoupled by a motioninterlocking mechanism to prevent independent movements of the parts,including these armatures, and to subject them to counteraction one byanother under shock or vibration. To this end, the interlockingmechanism is composed of pins 15 and 16, made of a non-magnetic materialsuch as stainless steel, coupled one to the other by rocker members 17and 18 Pin 15 is secured to armature by a tight fit with integral sleeve19 and it passes loosely through armature 5 due to the large opening insleeve 21. Pin 16 is secured to armature 5 by a tight fit in flange 2tbut passes loosely through flange 19 of armature 4 by reason of anenlarged opening 22. A contact actuating arm 24 is secured to armature 4by reason of a tight fit but passes loosely through an enlarged centralopening 25 in armature 5.

An end plate 26 made of a non-magnetic material such as brass is driventightly into sleeve member 19 and is keyed to the same at a plurality ofpoints designated 27. Similarly, an end plate 28, also made ofnon-magnetic ma terial such as brass, is tightly driven into theopposite sleeve member 11 and is also keyed at points designated 27' tothis sleeve member. End plates 26 and 2.8 are provided with openings and36 respectively of a larger diameter than contact actuating arm 24 whichcarries rockers 17 and 13. Anvils 31 and 32 are formed upon the insideface of end plates 26 and 28 and the openings 29 and 30 extendtherethrough. These anvils 31 and func tion as a mounting or point aboutwhich rockers 17 and 18 rock or pivot when moved by pins 15 and 16.

Contact actuating arm 24 projects forwardly through end plate 23 andcarries an insulating sleeve 35 supporting an insulating collar 36.Anchored in collar 36 are the inner tips of a plurality of springcontact arms 37 carrying movable contacts 38 adapted to effect amake-and-break action with contacts 39 carried on a plurality of springfingers 40 suitably attached to an inner row of terminal connectors 41disposed in a header 4-2 by glass seals 43. Spring contact members 37are likewise carried on similar terminal connectors 44 mounted in anouter row in header 42 by glass seals 45. A third set of contacts 88normally engaged by movable contacts 38, when the relay is de-energized,is carried by a set of spring members 86 also carried by terminalconnectors 87 arranged in an outer row but staggered between outerconnectors 44.

When it is desirable to seal all contacts and interior parts andpossibly pressurize the interior with an inert gas such as dry nitrogenor helium gas, header 42 may be carried in a gas-tight case 46 ofmagnetic material that serves to complete the magnetic field when coil 7is energized. A fill tube 47 is fixed to header 42 and provides achamber 48 for a contact return spring 49. Spring 49 lies betweenshoulder 56 of filler tube 4-7 and shoulder 51 of a sleeve 52 disposedbetween sleeve 35 and spring 49. As is well understood in the art, theinterior of case 46 may be evacuated through fill tube 47 and thencharged with an inert gas under pressure, fill tube 47 being sealed atits tip 55.

To obtain optimum performance of the relay, magnetic gaps 56 and 57 musthave a predetermined physical and magnetic relationship to the magneticgap 59 between armatures 4 and 5. Inasmuch as the magnetic forcedeveloped in gaps 56 and 57 when coil 7 is energized works against theforce produced in gap 59, the former gaps may be referred to as backgaps. The relationship between gap 59 and gaps 56 and 57 required foroptimum relay operation is that the physical dimensions of gaps 56 and57 must be such that the magnetic forces developed thereby aresubstantially equal, and will be less than the magnetic force developedacross gap 59.

In assembling the relay, spool end 8 and end plate 26, and spool end 9and end plate 28 may be fitted to sleeves and 11 respectively. Next,sleeve 12 may be fitted onto sleeve 11. When this is accomplished,rocker arm 18, ac tuating arm 24, armatures i and 5, withinterconnecting pins and 16 respectively, spacer 6, and rocker arm 17may be assembled and inserted into sleeve 12. Fnally, the subassembly ofsleeve 16, spool end S and end plate 26 is fitted to the open end ofsleeve 12 by inserting the end of sleeve 10 into sleeve 12 until the endof actuating arm 24 enters the opening 29 of end plate 26. At this stageof assembly the motion interlocking mechanism comprised of pins 15 and16 and rocker arms 17 and 18 is totally enclosed and is characterized byloose interplay resulting from lack of interengagement at all of theintended bearing points between the pins and rocker arms. Thisundesirable condition can be remedied, however, and final assembly andadjustment to eliminate loose interplay may be effected easily byapplying the method of this invention.

In Fig. 2 an apparatus for use in practicing this invention isillustrated. With this device, the necessary final.

assembly and adjustment of the concealed armature assembly can be made.This apparatus comprises a fixture in the form of two fixed brackets 61and 62 adapted to receive the relay before coil 7 is wound about sleeve12. Contact actuating arm 24 projects through an enlarged opening 63 inbracket 62 and has a clamp 64 secured thereto near its outer end. Atopposite end of the relay is a permanent magnet 65 engaging a threadedshaft 66 carried in bracket 61. Permanent magnet 65 is arranged indriving relation with threaded shaft 66. At the opposite end, clamp 64is adapted also to carry a permanent magnet 68. Clamp 64 and thispermanent magnet 68 are mounted on a resilient arm 69 anchored in base70. Arm 69 is flexed back and forth by a connecting rod 71 driven by arotating wheel 72. A pickup coil 73 is mounted over permanent magnet 68.As permanent magnet 68 is swept.

back and forth under coil 73, it generates a voltage which is indicatedon meter 74. Meter 74 is connected in a relay circuit defined by wires75 and 76 so that a relay 77 may be energized to close switch 78 in thecircuit of an electric motor 79 adapted to drive a gear 80 in mesh witha gear 81 on shaft 82 connected to threaded shaft 66.

Figs. 2 and 3 illustrate the relay carried between brackets 61 and 62with permanent magnet 65 in driving relation with threaded shaft 66. InFig. 3, shaft 66 is shown provided with a hand knob 85 while in Fig. 2shaft 66 is driven by motor 79 through gears 80 and S1 and shaft 82. Ineither case, the contact actuating arm 24 proiects through opening 63 inbracket 62 and permanent magnet 65 creates a magnetic field causingarmatures i and 5 to move toward each other and against spacer 6. If anylooseness or clearance exists between rockers 17 and 18 and therespective ends of interconnecting pins 15 and 16, the movement ofcontact actuating arm 24 will not secure optimum performance of therelay in the closing action of contacts 38 and 39. Such clearance orlooseness will also produce magnetic gaps 56 and 57 that are too small,and, therefore, are not in proper ratio with center gap 59. I have foundthat the proper ratio of these gaps may be established when a magneticfield is created by permanent magnet 65, the armatures 4 and 5 are drawntogether against spacer 6, and the parts of the relay are moved togetherthrough application of pressure at part 65 until the ends ofinterconnecting pins 15 and 16 engage the rocker members 17 and 18without causing a tendency toward binding or stiffness in relayoperation. With the parts made according to dimension, the sleeves 10,11, and 12 may be assembled tightly together, and the proper ratio ofthe gaps assured. Sleeve 12 may then be tack-welded about its peripheralends with sleeves 10 and 11 to lock all the parts into a permanent spoolunit. The pressure applied to magnet 65 should be just enough toeliminate looseness, the engagement between the rockers 17 and 18 andthe interconnecting pins 15 and 16 being just snugly made but not tight.In other words, any pressure applied at the point of engagement betweenthese parts should be insufficient to produce a tendency toward bindingor stiffness in their interaction.

In the form of apparatus shown in Fig. 2, clamp 64 in combination withflexible arm 69 may move the con tact actuating arm 24 back and forth togenerate 21 voltage at pickup coil 73. The amplitude of the generatedvoltage will indicate the amount of movement of contact actuating arm24. If there is movement or looseness, the relay circuits 75 and 76 willclose and actuate relay 77 to close switch 78. Thereupon, the motor 79will drive threaded shaft 66 forwardly through the gear connections 80,81 and 82. This forward movement of threaded connection 66 will move therelay parts together enough to remove any clearance betweeninterconnecting pins 15 and 16 and the rocker members 17 and 18. As soonas the clearance is eliminated, contact actuating arm 24 will no longermove, and, consequently, no voltage will be generated at coil 73 andrelay '77 will be de-energized to stop operation of motor 79.

When the looseness or clearance is thus eliminated between theinterconnecting pins 15 and 16 and the rocker arms 17 and 18, and thearmatures 4 and 5 have been centered by being drawn together againstspacer 6, it will be found that air gaps 56 and 57 will be in properratio to center air gap 59. When permanent magnet 65 is removed, and thearmatures 4 and 5 are returned to the de-energized position, as whencontact return coil spring 49 is assembled and in position, the centralmagnetic gap 59 may then be substantially greater than the back gaps 56and 57, this being shown in Fig. 1. It is desirable to make back gaps 56and 57 as small as possible so that the reluctance of the magnetic pathsbetween sleeve and armature 4, and sleeve 11 and armature 5 may beminimized.

It will be apparent from the foregoing description that this method offinally assembling and adjusting totally enclosed parts of the relaywill produce optimum performance of the relay under any and all severeconditions of use. The method is simple and very effective and quicklyand accurately removes this objectionable looseness Without applying anyexcessive pressure at the points of engagement of pins 15 and 16 withrockers 26 and 28. The action of the movable contacts 38 is alwayspositive and makes proper engagement each time the relay is energizedwith contacts 39.

Without further elaboration, the foregoing will so fully explain thecharacter of my invention that others may, by applying currentknowledge, readily adapt the same for use under varying conditions ofservice, without eliminating certain features, which may properly besaid to constitute the essential items of novelty involved, which itemsare intended to be defined and secured to me by the following claims.

I claim:

1. A method of adjustably assembly parts of a relay having spool endsand a sleeve arranged in a fixed relation therebetween, axially alignedmagnetic plungers disposed in the spool between said ends, a pair ofpins for interconnecting said plungers to prevent independent movementsthereof and to subject them to counteraction one by another under shockor vibration, a centrally disposed contact actuating rod movable by saidplungers, a spacer on said actuating rod between said plungers,pivotally carried rockers on said actuating rod for engaging the ends ofsaid interconnecting pins, and anvils at said spool ends against whichsaid rockers pivot, which method of adjustably assembling said relayparts to eliminate looseness between said rockers and saidinterconnecting pins comprises: magnetically energizing said plungers tomove them toward each other and against said spacer, then moving atleast one of said anvils toward said rockers until the ends of saidinterconnecting pins engage both of said rockers.

2. A method of adjustably assembling parts of a relay having spool endsand a sleeve therebetween arranged in a fixed relation, axially alignedmagnetic plungers disposed in the spool between said ends, a pair ofpins for interconnecting said plungers to prevent independent movementsthereof and to subject them to counteraction one by another under shockor vibration, a centrally disposed contact actuating rod movable by saidplungers, a. spacer on said actuating rod between said plungers,pivotally carried rockers on said actuating rod for engaging the ends ofsaid interconnecting pins, and anvils at said spool ends against whichsaid rockers pivot, the method of assembling said relay parts toeliminate looseness between said rockers and said interconnecting pins,which method comprises: magnetically energizing said plungers to movethem toward each other and against said spacer, then moving at least oneof said anvils toward said rockers, and simultaneously testing saidactuating rod for said looseness until both ends of said interconnectingpins engage both of said rockers.

3. A method of adjustably assembling parts of a relay having spool endsand a sleeve therebetween arranged in a fixed relation, axially alignedmagnetic plungers disposed in the spool between said ends, a pair ofpins for interconnecting said plungers to prevent independent movementsthereof and to subject them to counteraction one by another under shockor vibration, a centrally disposed contact actuating rod movable by saidplungers, a spacer on said actuating rod between said plungers,pivotally carried rockers on said actuating rod for engaging the ends ofsaid interconnecting pins, and anvils at said spool ends against whichsaid rockers pivot, which method of adjustably assembling said relayparts to eliminate looseness between said rockers and saidinterconnecting pins comprises: magnetically energizing said plungers tomove them toward each other and against said spacer, then moving saidrockers toward said pins until the ends of said pins engage saidrockers.

4. A method of adjustably assembling parts of a relay having spool endsand a sleeve arranged in a fixed relation therebetween, axially alignedmagnetic plungers disposed in the spool between said ends, a pair ofpins for interconnecting said plungers to prevent independent movementsthereof and to subject them to counteraction one by another under shockor vibration, a centrally disposed contact actuating rod movable by saidplungers, a spacer on said actuating rod between said plungers,pivotally carried rockers on said actuating rod for engaging the ends ofsaid interconnecting pins, and anvils at said spool ends against whichsaid rockers pivot, which method of adjustably assembling said relayparts to eliminate looseness between said rockers and saidinterconnecting pins comprises: magnetically energizing said plungers tomove them toward each other and against said spacer, then moving saidrockers toward said pins until the ends of said pins engage both of saidrockers and the magnetic gap between said plungers is centrallypositioned between said spool ends.

5. A method for adjustably assembling parts of a relay having spoolends, sleeve members carrying said ends and a sleeve spanning saidmembers and locking them with said ends into a rigid unit, a centrallydisposed contact actuating rod, axially aligned magnetic plungersdisposed on said actuating rod in said sleeve, a spacer on saidactuating rod between said plungers, a pair of pins for interconnectingsaid plungers to prevent independent movements thereof and to subjectthem to counteraction one by another under shock or vibration, rockermembers on said actuating rod for engaging the ends of saidinterconnecting pins, and pivotal mountings for said rocker members,which method of adjustably assembling said relay parts to eliminatelooseness between said rockers on said interconnecting pins comprises:magnetically energizing said plungers to move them toward each other,and against said spacer, then effecting relative movement of saidpivotal mountings to move the said rocker members until both ends ofsaid interconnecting pins engage both of said rocker members and saidplungers and the magnetic gap between said plungers is substantiallycentered between said spool ends.

6. A method for adjustably assembling parts of a relay having spoolends, sleeve members for carrying said ends and a sleeve spanning saidmembers and for rigidly inter locking said members with said ends toform a rigid spool, a centrally disposed contact actuating rod, axiallyaligned magnetic plungers disposed on said actuating rod in said spool,a spacer on said actuating rod between said plungers, a pair of pins forinterconnecting said plungers to prevent independent movements thereofand to subject them to counteraction one by another under shock orvibration, rocker members on said actuating rod for engaging the ends ofsaid interconnecting pins, and pivotal mountings for said rockermembers, which method of adjustably assembling said relay parts toeliminate looseness between said rockers and said interconnecting pinscomprises: magnetically energizing said plungers to move them towardeach other and against said spacer; then effecting relative movement ofsaid pivotal mountings to move the said rocker members until both endsof said interconnecting pins engage both of said rocker members withoutproducing stifi'ness of rocker action or a tendency to bind, and saidplungers and the magnetic gap between said plungers is substantiallycentered between said spool ends; and thereafter rigidly fixing saidsleeve to said sleeve members to lock them together.

7. A method for adjustably assembling parts of a relay having spoolends, sleeve members for carrying said ends and a sleeve spanning saidmembers and for rigidly interlocking said members with said ends to forma rigid unit, a centrally disposed contact actuating rod, axiallyaligned magnetic plungers disposed in said spool between said ends onsaid actuating rod, a spacer on said actuating rod between saidplungers, a pair of pins for interconnecting said plungers to preventindependent movements thereof and to subject them to counteraction oneby another under shock or vibration, rocker members on said actuatingrod for engaging the ends of said interconnecting pins, and pivotalmountings for said rocker members, which method of adjustably assemblingsaid relay parts to eliminate looseness between said rockers and saidinterconnecting pins comprises; magnetically energizing said plungers tomove them toward each other and against said spacer; then effectingrelative movement of said pivotal mountings toward said rocker membersuntil both ends of said interconnecting pins engage both of said rockermembers without pressure and said plungers and the magnetic gap betweensaid plungers is substantially centered between said spool ends; andthereafter tack welding said sleeve to said sleeve members.

8. In the assembly of an inaccessible counteracting mechanism totallysurrounded by an enclosure made of magnetic material, said mechanismhaving first and sec ond plungers of magnetic material, an actuating pincoupled to one of said plungers and normally reciprocable through thewall of said enclosure, said plungers being in magnetic relation to eachother and to the walls of said enclosure and slidably operable on afour-sided, rockable, linkage having opposite sides formed of first andsecond pins and opposite ends formed of first and second rocker armspivoted on opposite inner walls of said enclosure for engaging at theirends the ends of said pins, said first pin being fixedly attached tosaid first plunger and said second pin being fixedly attached to saidsecond plunger, whereby a force tending to cause movement of the saidplungers in the same direction will tend to rock the linkage in oppositedirections, a method of adjusting said enclosed mechanism to eliminateloose interplay between said pins and said rocker arms without causingstifiness or a tendency to bind in the operation of said linkage, thesaid method comprising: applying a magnetic field to said enclosure todevelop magnetic pull between said plungers sufficient to cause saidplungers to slide together; while maintaining said magnetic field,applying suificient pressure to the said opposite walls of the enclosureto move the said rocker arms toward the ends of said pins; and whilemaintaining said magnetic field and said plungers together, applying areciprocatory force to the protruding end of said actuating pin in orderto detect the presence or absence of loose interplay in the saidlinkage.

References Cited in the file of this patent UNITED STATES PATENTS2,273,736 Raymond et al. Feb. 17, 1942 2,677,875 White et al. May 11,1954 2,720,693 Charbonneau et al. Oct. 18, 1955 L pt

